Mr. Muslim was formerly the co-president of the Democratic Union Party (known as the P.Y.D.), the political arm of the Kurdish Peoples Protection Units, or Y.P.G., in Syria. Turkey claims the P.Y.D. and Y.P.G. are part of the Turkish-based Kurdistan...

Turkey mobilized hundreds of C.I.A.-trained Syrian Arab fighters from the opposition Free Syrian Army to spearhead its attack and bombarded the enclave with jets and artillery fire. But Turkish forces have struggled to make headway against the well-prepared Kurdish fighters....